diff options
Diffstat (limited to 'engine/overworld/oam.asm')
| -rw-r--r-- | engine/overworld/oam.asm | 161 |
1 files changed, 67 insertions, 94 deletions
diff --git a/engine/overworld/oam.asm b/engine/overworld/oam.asm index e81375a3..ff85eb3e 100644 --- a/engine/overworld/oam.asm +++ b/engine/overworld/oam.asm @@ -1,14 +1,12 @@ -PrepareOAMData: ; 499b (1:499b) +PrepareOAMData: ; Determine OAM data for currently visible ; sprites and write it to wOAMBuffer. -; Yellow code has been changed to use registers more efficiently -; as well as tweaking the code to show gbc palettes ld a, [wUpdateSpritesEnabled] dec a jr z, .updateEnabled - cp $ff + cp 0 - 1 ret nz ld [wUpdateSpritesEnabled], a jp HideSprites @@ -19,10 +17,10 @@ PrepareOAMData: ; 499b (1:499b) .spriteLoop ld [hSpriteOffset2], a - - ld e, a + ld d, wSpriteStateData1 / $100 - + ld a, [hSpriteOffset2] + ld e, a ld a, [de] ; c1x0 and a jp z, .nextSprite @@ -42,22 +40,16 @@ PrepareOAMData: ; 499b (1:499b) jr c, .usefacing ; unchanging - ld a, $0 + and $f + add $10 ; skip to the second half of the table which doesn't account for facing direction jr .next .usefacing and $f .next -; read the entry from the table - ld c, a - ld b, 0 - ld hl, SpriteFacingAndAnimationTable - add hl, bc - add hl, bc - ld a, [hli] - ld h, [hl] ld l, a + ; get sprite priority push de inc d @@ -69,46 +61,65 @@ PrepareOAMData: ; 499b (1:499b) ld [hSpritePriority], a ; temp store sprite priority pop de +; read the entry from the table + ld h, 0 + ld bc, SpriteFacingAndAnimationTable + add hl, hl + add hl, hl + add hl, bc + ld a, [hli] + ld c, a + ld a, [hli] + ld b, a + ld a, [hli] + ld h, [hl] + ld l, a call GetSpriteScreenXY ld a, [hOAMBufferOffset] - add [hl] - cp $a0 - jr z, .hidden - jr nc, .asm_4a41 -.hidden - call Func_4a7b - ld [wd5cd], a - ld a, [hOAMBufferOffset] - ld e, a ld d, wOAMBuffer / $100 .tileLoop - ld a, [hli] - ld c, a -.loop ld a, [hSpriteScreenY] ; temp for sprite Y position add $10 ; Y=16 is top of screen (Y=0 is invisible) add [hl] ; add Y offset from table ld [de], a ; write new sprite OAM Y position inc hl - inc e ld a, [hSpriteScreenX] ; temp for sprite X position add $8 ; X=8 is left of screen (X=0 is invisible) add [hl] ; add X offset from table - ld [de], a - inc hl inc e - ld a, [wd5cd] - add [hl] - cp $80 - jr c, .asm_4a1c + ld [de], a ; write new sprite OAM X position + inc e + ld a, [bc] ; read pattern number offset (accommodates orientation (offset 0,4 or 8) and animation (offset 0 or $80)) + inc bc + push bc ld b, a - ld a, [$fffc] - add b -.asm_4a1c + + ld a, [wd5cd] ; temp copy of c1x2 + swap a ; high nybble determines sprite used (0 is always player sprite, next are some npcs) + and $f + + ; Sprites $a and $b have one face (and therefore 4 tiles instead of 12). + ; As a result, sprite $b's tile offset is less than normal. + cp $b + jr nz, .notFourTileSprite + ld a, $a * 12 + 4 + jr .next2 + +.notFourTileSprite + ; a *= 12 + sla a + sla a + ld c, a + sla a + add c + +.next2 + add b ; add the tile offset from the table (based on frame and facing direction) + pop bc ld [de], a ; tile id inc hl inc e @@ -118,19 +129,15 @@ PrepareOAMData: ; 499b (1:499b) ld a, [hSpritePriority] or [hl] .skipPriority - and $f0 - bit 4, a ; OBP0 or OBP1 - jr z, .spriteusesOBP0 - or %100 ; palettes 4-7 are OBP1 -.spriteusesOBP0 - ld [de], a inc hl + ld [de], a inc e - dec c - jr nz, .loop + bit 0, a ; OAMFLAG_ENDOFDATA + jr z, .tileLoop ld a, e ld [hOAMBufferOffset], a + .nextSprite ld a, [hSpriteOffset2] add $10 @@ -138,33 +145,28 @@ PrepareOAMData: ; 499b (1:499b) jp nz, .spriteLoop ; Clear unused OAM. -.asm_4a41 + ld a, [hOAMBufferOffset] + ld l, a + ld h, wOAMBuffer / $100 + ld de, $4 + ld b, $a0 ld a, [wd736] bit 6, a ; jumping down ledge or fishing animation? - ld c, $a0 + ld a, $a0 jr z, .clear ; Don't clear the last 4 entries because they are used for the shadow in the ; jumping down ledge animation and the rod in the fishing animation. - ld c, $90 + ld a, $90 .clear - ld a, [hOAMBufferOffset] - cp c - ret nc - ld l, a - ld h, wOAMBuffer / $100 - ld a, c - ld de, $4 ; entry size - ld b, $a0 -.clearLoop + cp l + ret z ld [hl], b add hl, de - cp l - jr nz, .clearLoop - ret + jr .clear -GetSpriteScreenXY: ; 4a5f (1:4a5f) +GetSpriteScreenXY: ; 4bd1 (1:4bd1) inc e inc e ld a, [de] ; c1x4 @@ -186,32 +188,6 @@ GetSpriteScreenXY: ; 4a5f (1:4a5f) ld [de], a ; c1xb (x) ret -Func_4a7b: ; 4a7b (1:4a7b) - push bc - ld a, [wd5cd] ; temp copy of c1x2 - swap a ; high nybble determines sprite used (0 is always player sprite, next are some npcs) - and $f - - ; Sprites $a and $b have one face (and therefore 4 tiles instead of 12). - ; As a result, sprite $b's tile offset is less than normal. - cp $b - jr nz, .notFourTileSprite - ld a, $a * 12 + 4 ; $7c - jr .done - -.notFourTileSprite - ; a *= 12 - add a - add a - ld c, a - add a - add c -.done - pop bc - ret - -INCLUDE "engine/oam_dma.asm" - _IsTilePassable:: ; 4aaa (1:4aaa) ld hl,W_TILESETCOLLISIONPTR ; pointer to list of passable tiles ld a,[hli] @@ -222,11 +198,8 @@ _IsTilePassable:: ; 4aaa (1:4aaa) cp a,$ff jr z,.tileNotPassable cp c - jr nz,.loop - xor a - ret + ret z + jr .loop .tileNotPassable scf - ret - -INCLUDE "data/collision.asm" ; probably
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